Evaluation of techniques for estimating the yield of irrigated pastures intensively grazed by dairy cows. 1. Visual assessment

1984 ◽  
Vol 24 (126) ◽  
pp. 300 ◽  
Author(s):  
CR Stockdale
Keyword(s):  
Dairy Cows ◽  
Dairy Cow ◽  
Dry Matter ◽  
Sampling Technique ◽  
Visual Assessment ◽  
Sampling Procedure ◽  
Double Sampling ◽  
Assessment Technique ◽  
Coefficients Of Variation ◽  
The Mean

A visual assessment technique was evaluated for estimating pre- and post-grazing pasture yields in experiments in which dairy cows rotationally graze irrigated pastures. Visual assessment, when associated with the harvesting of standard quadrats, accounted for 62.3 and 68.4% of the variability in pre- and post-grazing yield, respectively. The mean residual standard deviations associated with the pre- and post-grazing regressions were 490 and 395 kg dry matter/ha and, when the variable yields were taken into account, these represented coefficients of variation of 15.6 and 19.0%, respectively. By using the coefficient of variation as the criterion for precision, pre-grazing regressions were significantly more precise than post-grazing regressions. In practice, visual assessment by a double sampling procedure can be used to estimate pre- and post-grazing yields in dairy cow grazing experiments where herbage intakes and growth rates are required, provided sufficient readings are taken to allow an acceptable level of precision. It is suggested that about ten standards are required to formulate a calibration regression regardless of whether or not the pasture to be assessed has been grazed. Although the double sampling technique may be suitable for research purposes, it has been demonstrated that the completely subjective eye appraisal, often used by farmers and their advisers for feed budgeting, can result in many incorrect assessments. A more objective technique needs to be developed for this purpose.

MEASUREMENT OF DUODENAL FLOW IN DAIRY COWS BY EITHER TOTAL COLLECTION OR SPOT SAMPLING, USING A SPECIAL CANNULA

1984 ◽  
Vol 64 (5) ◽  
pp. 116-117 ◽  
Author(s):  
K. ROHR ◽  
M. BRANDT ◽  
P. LEBZIEN ◽  
H. SCHAFFT
Keyword(s):  
Organic Matter ◽  
Dairy Cows ◽  
Key Words ◽  
Dry Matter ◽  
Sampling Technique ◽  
Sampling Procedure ◽  
Single Marker ◽  
The Mean ◽  
Special Cannula ◽  
Friesian Cows

Duodenal flow as derived from total collection and spot sampling was compared in three Friesian cows, using a re-entrant cannula without transecting the intestine. Cr2O3 was used as a single marker. Small differences in flow of dry matter, organic matter and nitrogen indicate that the spot sampling procedure may render valid results. The mean recovery of Cr2O3 was 96.7%. Key words: Cattle, duodenal flow, sampling technique, marker

Evaluation of techniques for estimating the yield of irrigated pastures intensively grazed by dairy cows. 2. The rising plate meter

1984 ◽  
Vol 24 (126) ◽  
pp. 305 ◽  
Author(s):  
CR Stockdale
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
Visual Assessment ◽  
Matter Content ◽  
Dry Matter Content ◽  
Botanical Composition ◽  
Assessment Technique ◽  
Grazed Pastures ◽  
Number Of Factors ◽  
Short Period

A semi-automatic rising plate meter, the Ellinbank Pasture Meter (EPM) was used to estimate herbage yields of the three most common types of irrigated pasture intensively grazed by dairy cows in northern Victoria. While there were only small differences in precision between the pasture types, yields of pre-grazed pastures were measured more precisely than yields of post-grazed pastures. The EPM also estimated pre-grazing yield more precisely than a visual assessment technique, while the two techniques were similar for estimating post-grazed herbage. A number of factors, including dry matter content of the herbage, botanical composition, season, and lodging due to trampling were shown to influence pre- and post-grazing regressions. It was concluded that pooled regressions were therefore unsuitable for research purposes unless the pooling was for a relatively short period only. Pre- and post-grazing data can be pooled for periods of up to two months to allow the estimation of pasture growth rates at various points of time between grazings. An alternative method of obtaining yield estimates has been proposed in which it is not necessary to develop a regression. This method relies on cutting quadrats in each plot that are representative of the yield and composition of the plot. While this method can circumvent some of the problems associated with the factors that influence the yield-height relationship, severe lodging due to trampling of the sward may preclude the use of the EPM regardless of method.

The effect of root feeding on the intake and production of dairy cows

1961 ◽  
Vol 28 (1) ◽  
pp. 67-74 ◽  
Author(s):  
M. E. Castle ◽  
A. D. Drysdale ◽  
R. Waite
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
Feeding Trial ◽  
Crude Fibre ◽  
Fodder Beet ◽  
Grass Silage ◽  
Grassland Conservation ◽  
The Mean ◽  
Intensively Managed ◽  
Made In

SummarySince grassland conservation crops are normally bulky fibrous feeds and often limit the appetite and nutrient intake of dairy cows, a feeding trial was made in which a basal ration of hay and grass silage was compared with similar rations containing roots. Three rations were compared in a 12–week winter feeding trial using twelve Ayrshire cows. Ration A consisted of 8 lb of hay and 65 lb of grass silage daily, whilst rations B and C contained 30 and 60 lb of fodder-beet, respectively, in addition. With all three rations concentrates were given at 3½ lb per 10 lb of milk. The total weights of dry matter consumed per day were 29·1, 32·5 and 35·4 lb, respectively, for rations A, B and C and were significantly different. For every 1 lb of additional fodder-beet dry matter eaten the decline in the amount of basal feeds consumed was 0·45 lb. The largest effect was on the silage which fell from 10·8 lb of silage dry matter per day for ration A to 8·8 lb for ration B and 6·8 lb for ration C.The weight of starch equivalent (S.E.) given per day increased significantly from 18·1 lb for treatment A to 22·2 lb for treatment C, whilst at the same time the total weight of crude fibre and lignin eaten decreased significantly in the rations containing fodder-beet.The mean daily milk yields for rations A, B and C were 37·4, 39·2 and 38·5 lb, respectively, with a response of 0·9 lb milk per 1 lb of extra S.E. given between rations A and B but no further response between rations B and C. The fat percentages of the milk were not significantly different for the three rations whereas the solidsnot-fat (S.N.F.) varied significantly from 8·58% for ration A to 8·77% for ration C— a response of 0·05% S.N.F. for each additional 1 lb of S.E. The change in the S.N.F. was mainly in the protein fraction of the milk. The cows were significantly heavier when on ration C than when on ration A.The effect of feeding roots on the appetite of the cow and on the resulting milk quality, and the problems of growing roots on intensively managed grassland farms are briefly discussed.

Headspace Gas Chromatographic Method for Determination of Ethanol in Canned Salmon: Collaborative Study

1986 ◽  
Vol 69 (3) ◽  
pp. 524-526
Author(s):  
Thomas A Hollingworth ◽  
Harold R Throm ◽  
Marleen M Wekell ◽  
William F Trager ◽  
Michael W O’Donnell ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Sampling Technique ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Headspace Gas ◽  
The Mean ◽  
Gas Chromatographic Method

Abstract Six laboratories collaboratively studied a headspace gas chromatographic method for determination of ethanol in the aqueous phase of canned salmon. Ethanol is determined by a headspace sampling technique with tert-butanol as the internal standard, using a gas chromatograph equipped with a Super Q column and a flame ionization detector. With outliers excluded, the mean recoveries from samples spiked with 25.1 and 78.4 ppm ethanol were 112 and 110%, respectively. For the 4 sample pairs quantitated, repeatability coefficients of variation ranged from 1.42 to 4.25% and reproducibility coefficients of variation from 2.55 to 8.09%, with 3 of the 4 reported values less than 5%. The method has been adopted official first action.

Studies in grazing management V. Further determination of the nutrient intake of dairy cows under close-folding and rotational methods of grazing

1952 ◽  
Vol 42 (3) ◽  
pp. 314-321 ◽  
Author(s):  
R. Waite ◽  
W. Holmes ◽  
J. Boyd
Keyword(s):  
Standard Deviation ◽  
Chemical Composition ◽  
Dairy Cows ◽  
Nutrient Intake ◽  
Dry Matter ◽  
Balance Sheet ◽  
Adequate Quantity ◽  
The Mean ◽  
The Relationship

1. The experiments started in 1949 to determine the weight and chemical composition of the herbage dry matter eaten by two groups of dairy cows grazing under a rotational and a close-folding system of management have been continued in 1950.2. Good-quality herbage was fed in adequate quantity to both groups for 20 weeks, in four fiveweekly periods allowing a double change-over system for the groups. The weights of protein, fibre, other extractives, lignin and minerals eaten daily by the close-folded group were determined. Difficulty in obtaining truly representative herbage samples from the rotational paddock made such detailed analyses for the rotationally grazed cattle not worth while.3. The weight of dry matter eaten by the closefolded cows was remarkably constant, the mean was 26 lb./cow/day and the standard deviation ±2·7 lb. The weight eaten by the rotationally grazed cows was more difficult to measure and appeared to vary considerably, the average being 31 lb. dry matter/ cow/day, and the standard deviation ±3·1 lb. Reasons are suggested why this figure of 31 lb. may be at least 5% too high.4. The relationship between the chemical composition of herbage as cut for sampling and the probable composition of the herbage as eaten by the grazing animal is discussed. Correction curves are given to convert the protein and fibre contents of herbage as cut in these experiments to values corresponding to those in the herbage as eaten.5. An attempt has been made to provide a balance sheet, in terms of D.C.P. and S.E., of animal production against nutrient intake. A deficiency of both protein and energy existed during the first spring period in both 1949 and 1950 (according to presentday standards), and although the protein balance became positive later in the season, the energy provided by the grass eaten was still barely adequate.6. Mineral balances calculated for the closefolded cows showed deficiencies of both calcium and phosphorus during the period of high milk yield, with the balances becoming positive later in the grazing season.

Effect of the level of concentrate supplementation, herbage allowance and milk yield at turn-out on the performance of dairy cows in mid lactation at grazing

2001 ◽  
Vol 73 (1) ◽  
pp. 171-181 ◽  
Author(s):  
L. Delaby ◽  
J. L. Peyraud ◽  
R. Delagarde
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Dairy Cow ◽  
Milk Fat ◽  
Dry Matter ◽  
Milk Protein ◽  
Body Weight Gain ◽  
Fresh Weight ◽  
Concentrate Supplementation ◽  
Cow Performance

AbstractIn order to establish the response of dairy cow performance to concentrate supplementation in contrasting grazing conditions and for cows differing in milk yield at turn-out, three experiments were conducted. Each year, two levels of herbage allowance were studied in interaction with four (experiment 1) or three (experiments 2 and 3) levels of concentrate on two groups of 30 to 40 mid-lactation Holstein cows producing between 20 and 46 kg milk at turnout. Amount of concentrate and herbage allowance ranged from 0 to 6 kg fresh weight and from 12 to 22 kg dry matter (DM) per cow per day respectively. The supplementation led to average responses, per kg DM concentrate, of 104 kg milk, +66 g/day body-weight gain, +0·19 g/kg milk protein and -0·57 g/kg milk fat. These responses remained linear up to 4 or 6 kg according to the years and treatments. The response to the concentrate did not vary with the milk yield or composition at turn-out. The increase in the herbage allowance from 12 to 16 kg DM per cow per day (experiment 1) improved milk yield (+1·2 kg/day) and milk protein (+0·7 g/kg) while the increase from 16 to 22 kg DM (experiments 2 and 3) had less effect (+0·5 kg/day milk yield and +0·4 g/kg milk protein). There was no clear interaction between concentrate supplementation and herbage allowance. Under the usual conditions of spring pasture, with cows in mid lactation, the use of a constant level of concentrate at grazing proves to be a technique of some interest.

Grazed pasture parameters. II. Pasture dry-matter use in a stocking rate and grazing management experiment with dairy cows

1966 ◽  
Vol 67 (2) ◽  
pp. 211-216 ◽  
Author(s):  
A. G. Campbell
Keyword(s):  
Dairy Cows ◽  
Dairy Cow ◽  
Dry Matter ◽  
Grazing Pressure ◽  
Grazing Management ◽  
Dry Matter Intake ◽  
Small Scale ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Grazed Pasture

1. Dry-matter intake, pasture utilization and grazing pressure were studied over 3 years on a small-scale replica of a dairy cow grazing management x stocking rate trial.2. The four treatments were:(i) Controlled rotational grazing, light stocking rate (0.95 cow/acre).(ii) Controlled rotational grazing, heavy stocking rate (1.19 cow/acre).(iii) Uncontrolled, set stocked grazing, light stocking rate (0.95 cow/acre).(iv) Uncontrolled, set stocked grazing, heavy stocking rate (1.19 cows/acre).3. Mean D.M. intakes were: (i) 29, (ii) 21, (iii) 28 and (iv) 21 lb./cow per day. D.M. intake was reduced on average by 7 ± 2.1 lb./cow per day at the higher level of stocking.

scholarly journals KEEFEKTIFAN PEMBELAJARAN E-LEARNING BERBASIS WEBSITE PADA MATA KULIAH TEORI BILANGAN DI IKIP PGRI SEMARANG

2012 ◽  
Vol 4 (1) ◽  
pp. 91
Author(s):  
Muhammad Prayito
Keyword(s):  
Number Theory ◽  
Sampling Technique ◽  
Sampling Procedure ◽  
Education Students ◽  
Regression Test ◽  
E Learning ◽  
Independent Variable ◽  
The Mean ◽  
Positive Effect ◽  
Better Than

The aim of this study is to know the effectiveness of learning based on Web at Number Theory lesson at IKIP PGRI Semarang. The implementation is focused at  FPMIPA IKIP PGRI Semarang in fifth semester of mathematics education students which contain of  9 classes. Sampling technique in this study use convenience sampling procedure, where as the experimental is 5B and 5A as the control class and  5G as a class test. Independent variable of this research is the activity of student and learning result as dependent variable. The Data is obtained through observation and tests then we analyze by t test and regression test.. The results showed that implementation of learning achieve effective with characterized by: a) Mean of student learning result greater than KKM = 75, and in classical is more than 85% of students achieve point at 75. b) Effect of activity on the results of study is  means that the active variable (X) gives a positive effect on learning result (Y). The value of the effect of creativity on learning result can be  seen by R value in the table of Summary Model 0.867 = 86.7%.  The Value indicates that the creativity of students  affect learning result at 86.7%. c) The Mean of experimental class is 80.94 and 62.60 for the control class, so the class of experiments significantly better than the the control class. Based on the above explanation we conclude that learning based on web at Number Theory in Semarang PGRI IKIP is effective.

Effect of a fibrolytic enzyme preparation from Trichoderma longibrachiatum on the rumen microbial population of dairy cows

2002 ◽  
Vol 48 (1) ◽  
pp. 14-20 ◽  
Author(s):  
V L Nsereko ◽  
K A Beauchemin ◽  
D P Morgavi ◽  
L M Rode ◽  
A F Furtado ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Dairy Cow ◽  
Dry Matter ◽  
Enzyme Preparation ◽  
Microbial Population ◽  
Cellulolytic Bacteria ◽  
Maize Silage ◽  
Secondary Products ◽  
Trichoderma Longibrachiatum ◽  
Viable Bacteria

The effects of supplementing a dairy cow diet with incremental levels of a fibrolytic enzyme preparation (preparation B) from Trichoderma longibrachiatum on the rumen microbial population were investigated. Two cows fitted with rumen cannulae were each fed a diet containing barley-based concentrate (52%), maize silage (29%), and chopped alfalfa hay (19%), supplemented with 0, 1, 2, 5, or 10 L of preparation B per tonne of dry matter (DM). Preparation B stimulated numbers of total viable bacteria in a quadratic manner (P < 0.05), to approximately 230, 330, 390, and 250% at 1, 2, 5, and 10 L·t–1 DM, respectively. Preparation B increased the numbers of cellobiose-utilizing (P < 0.01), xylanolytic (P < 0.05), and amylolytic bacteria (P < 0.05), but had no effect (P > 0.05) on numbers of cellulolytic bacteria. However, when bacterial numbers enumerated on each substrate were expressed as a proportion of total viable bacterial numbers, only cellobiose utilizers were stimulated, and this stimulation was limited to the 1 L·t–1 DM level of preparation B (P < 0.05). The results of this study demonstrate that the inclusion of an exogenous fibrolytic enzyme preparation in dairy cow diets increased the numbers of rumen bacteria that utilize hemicelluloses and secondary products of cellulose digestion.Key words: rumen, fibrolytic enzymes, cellulase, xylanase, cellulolytic, xylanolytic.

Magnesium metabolism in the dairy cow. II. Metabolism during the spring grazing season

1958 ◽  
Vol 51 (2) ◽  
pp. 199-207 ◽  
Author(s):  
J. A. F. Rook ◽  
C. C. Balch
Keyword(s):  
Individual Differences ◽  
Dairy Cow ◽  
Dry Matter ◽  
Matter Content ◽  
Mature Stage ◽  
Dry Matter Content ◽  
Magnesium Metabolism ◽  
Grazing Season ◽  
The Mean

1. Three experiments are reported in which magnesium metabolism trials were carried out with milking cows that had been changed abruptly from typical winter rations to herbage cut freshly from swards at an early or at a more mature stage of growth and fed in the stall.2. The intake of herbage magnesium by individual animals varied from 9·5 to 15·2 g./day. Much of this variation was, however, associated more with differences in the palatability and dry-matter content of the herbage offered than with individual differences in appetite.3. The mean proportion of the ingested herbage magnesium excreted in the faeces was similar in all three experiments, being 82·3, 83·0 and 82·4% respectively. With any given sward there were, however, wide variations between individual animals in their utilization of herbage magnesium.4. The supply of ‘available’ magnesium to animals fed cut herbage in the stall varied from 0·5 to 4·2 g./day, as compared with values of from 2·6 to 10·5 g./day obtained previously (Rook et al. 1958) with cattle fed typical winter rations. In spite of this lower intake of ‘available’ magnesium, the animals maintained a positive magnesium balance.

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